A holder of lighting device is provided for receiving a lighting unit of the lighting device to be inserted and retained therein. The lighting unit includes an insertion portion that is insertable into the holder. The holder includes a clamp section, which defines a receiving and retaining space, and a base, which extends outwards and downwards from the clamp section. The clamp section includes a plurality of pawls that circumferentially surrounds a center of the receiving and retaining space and is engageable with and thus resiliently clamps the insertion portion of the lighting unit. The base can be stably positioned on a flat surface and the pawls resiliently clamp the insertion portion of the lighting unit so that the stability of positioning the lighting unit can be improved.